High bandwidth data transmission is challenging due to limited channel bandwidth.
Serializer/Deserializer (SerDes) links are commonly used to transfer data over a channel with frequency dependent signal degradation. This signal degradation leads to inter-symbol interference (ISI) which impairs the signal quality at a receiver. One way of compensating for signal distortion due to limited bandwidth is to add equalization functions at the SerDes links. Different equalization techniques may be used to compensate for this ISI in transmitters and receivers. One type of equalizer is a decision feedback equalizer (DFE) in a receiver, for example, which can compensate for ISI and is able to flatten the channel response without amplifying noise or cross-talk. One type of DFEs is an infinite impulse response (IIR) DFE which allows for multiple ISI terms to be removed.
Traditionally, 1/K-rate DFEs (e.g., half-rate, quarter-rate and the like) require data to be multiplexed back to full-rate before removing the ISI. The multiplexing back to full-rate requires additional power and adds a delay in the feedback path of the DFE which is detrimental at high-data rates, where DFEs are most useful.
Therefore, there is a need for improvements to methods and systems that compensate for problems related to ISI cancellation at high-data rates.